US3476253A - Washing machine support assembly - Google Patents

Description

Nov. 4, 1969 J, R. FOSLER ET AL 3,476,253

WASHING MACHINE SUPPORT ASSEMBLY 3 Sheets-Sheet l Filed Feb.

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WASHING MACHINE SUPPORT ASSEMBLY Filed Feb. 4, 1965 v 3 Sheets-Shee 2 l l l l l l INVENTORS John R. FBsJez 825.91405 6. f/zazpe MZKKM THEIR A T TORNEY Nov. 4, 1969 J, R, FOSLER ET AL 3,476,253

WASHING MACHINE SUPPORT ASSEMBLY Filed F'e. 4, 1965 5 Sheets-Sheet 5 r DEFLEC TION w sHoRE DuRoMsrsR HARD/V555 commessa/0N OAD (Pouups) THEIR ATTQRNEY United States Patent O 3,476,253 WASHING MACHINE SUPPORT ASSEMBEYv John R. Fosler and Verlos G. Sharpe, Dayton, 9h10, as-

signors to General Motors Corporation, Detroit, Mich.,

a corporation of Delaware Filed Feb. 4, 1965, Ser. No. 430,266 Int. Cl. B01d 21/26; B041] 7/00; F16f 15/10 U.S. Cl. 210-365 1 Claim ABSTRACT F THE DISCLOSURE A moving mass system including a spin tub rotatable on a spin shaft through a slip clutch drive mechanism below, and wherein the system is supported between the tub and the drive mechanism on a resilient cup shaped support of reduced spring rate and at its lower end on a freely relatively slidable snubber.

This invention relates to a domestic appliance and more particularly to an improved support arrangement for a roller drive mechanism for agitating and spinning of the type taught in the patent to Brucken 3,087,321, issued Apr. 30, 1963.

In clothes washers having a. solid tub rotatable for centrifuging water therefrom, it is desirable that the dynamic forces created during spinning be restrained from vibrating or moving the clothes washer cabinet. Prior systems directed to this problem are shown in the patents to Sisson 2,859,877 issued Nov. 11, 1958, and to Clark et al. 2,539,530 issued Jan. 30, 1951.

Accordingly, it is an object of this invention to provide in a clothes washer an improved support arrangement for a moving mass system comprising a spin tub and roller drive mechanism.

Another object of this invention is the provision for a moving mass spin tub system of an improved support arrangement comprising resilient support means connected to said moving mass system at a midpoint thereof for vertically supporting approximately half of the weight thereof and for absorbing some lateral dynamic forces eected lby the unbalanced rotation of the spin tub and comprising further a snubber at the bottom of said moving mass sys'tem for vertically supporting the remaining weight of said system and for absorbing the remaining lateral dynamic forces.

A further object of this invention is the provision of an improved snubber arrangement for an agitating and spinning drive mechanism which has improved assembly and reliability characteristics and which resists lateral excursions of said mechanism without denitely limiting the movement thereof.

A more general object of this invention is the provision of a support arrangement for a moving mass spin tub system which is designed to retain the water in said spin tub until after said moving mass system passes through the critical speed of the spin tub.

Another object is the provision of a suspension arrangement for a spin tub wherein the lateral deflection at an upper portion thereof is limited and the lateral deflection at a lower portion thereof is unlimited.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

FIGURE 1 is a sectional View, partly in elevation, of a clothes washer suitable for use with the improved moving mass support system of this invention;

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FIGURE 2 is a fragmentary sectional view taken along line 2 2 in FIGURE 1 showing the snubber portion of this invention;

FIGURE 3 is a fragmentary sectional view taken along line 3 3 in FIGURE 2;

FIGURE 4 is a fragmentary sectional view, partly in elevation, of the resilient mechanism support portion of this invention showing its condition when the spin tub is at standstill or in a balanced rotating situation;

FIGURE 5 is a fragmentary sectional view, partly in elevation, taken along line 5-5 in FIGURE 4;

FIGURE 6 is a fragmentary sectional view similar to FIGURE 4 and showing the mechanism support in a laterally stressed or distorted condition responsive to an unbalanced load in a rotating spin tub; and

FIGURE 7 is a graphic representation of the deflection curve for the mechanism support of FIGURE 4.

For use with this invention and with reference to FIGURE l, a clothes washer 20 is comprised of a control housing assembly 22 and a casing 24. The casing 24 is generally divided into a mechanism portion or compartment 26 and a washing compartment or Water container chamber 28. A generally centrally located bulkhead 30 separates the mechanism compartment 26 from the Water container chamber 28. Within the water container chamber 28 is a spin tub 34 having a top opening 36 and a plurality of centrifuging outflow ports 38. The ports 38 are designed to permit the egress of water from the tub 34 when the tub is rotated at high speed. For filling the tub 34 with water a conventional water supply system may be provided wherein a hot and cold water solenoid operated mixing valve is manifolded into a mixed water supply conduit terminating at a chute overlying the opening 36 of the tub. Within the tub 34, an agitator or pulsator 48 is adapted to reciprocate vertically to circulate or agitate the water in the tub. Thus, clothing placed within the tub 34 is washed as the agitating action of the pulsator 48 forces surging toroidal currents of washing fluid and detergent through the fabric. Conventional sequential operating timer means, shown generally at 50` on the control housing 22, may be included selectively to admit water to the tub 34, to spin the tub and to vertically reciprocate the agitator 0r pulsator 48.

:Roller drive mechanisms for selectively spinning a tub and reciprocating or oscillating an agitator are taught in the aforementioned Brucken patent, in Sisson Patents 3,060,712 issued Oct. 30, 1962, and 3,165,911 issued lan. 19, 1965, and in copending application Ser. No. 128,074 iiled July 3l, 1961, now Patent 3,174,596 patented March 23, 1965, and assigned to the same assignee as this invention. This invention is directed to a suspension and snubbing system for use in combination with these roller drive mechanisms, and more particularly with a slipping clutch drive mechanism of the type taught in concurrently vtiled application Ser. No. 430,264, now Patent 3,314,257 patented Apr. 18, 1967, one of which is shown generally at 51 in FIGURE 1, said system serving to retain the water in the spin tub until after the tub is accelerated through its critical speed in accordance with the teachings of this invention for reducing the critical speed thereof.

In general the roller drive mechanism 51 is suspended from a stationary shaft enclosing housing portion .54 which is connected to a resilient cup-shaped support member 56 and which encloses a spin shaft 55 and an agitate shaft 57. The support member 56, in turn, is a'lixed to an opening 58 in the bulkhead 30-a suitable sealing gasket Ibeing provided to effect a watertight connection therebetween. In order to dampen excessive gyrating or swinging movement of the agitate and spin mechanisms lower end, a snubber device or assembly 70` is used at the lower end of a moving mass system which includes the spin tub 34 and the roller drive mechanism 51.

The agitating and spinning mechanism `51 includes a H P., split phase, single speed 1725 r.p.m., four-pole reversible motor 60l with a -built in automatic reset type thermal overload protector. The motor, as well as other components of the roller drive mechanism, are supported in a snubber support bracket 72 which is connected at the top thereof to the tubular support housing 54 and, at the bottom thereof, has a snubber plate 74 of bright zinc plated steel which is mounted thereto by four screws 76.

The surface 78 of the plate must be at within 0.010 inch, smooth and free of burrs and imperfections or other protuberance which allow material to protrude above the surface. Further, the plate should have a chromate treatment and must be clean and free of dirt, oil and plating streaks.

The snubber assembly 70 consists of a snubber 80 and a snubber spring 82 held in a drawn cup portion 84 of a steel cabinet crossbrace 86. The crossbrace extends diagonally from one bottom corner of the clothes washer cabinet 24 to another corner thereof, thereby strengthening the cabinet as well as retaining the snubber.

The snubber 80 is formed of sintered brass alloy and has a friction pad portion `88 grooved for receiving wear particles, and a cylindrical sleeve Portion 90 having a downwardly faced opening formed by the terminal edge thereof. The pad portion mates closely with the flat surface 78 on the snubber plate '74. The sleeve portion forms a cavity which receives the upper end of the coil spring 82. A spring retainer 92 fastened to the crossbrace includes a drawn collar guide portion 94 for positioning the lower end of the spring. Thus the spring helps to center the snubber pad.

Interposed between the snubber sleeve 90 and the drawn cup -84 is a resilient bushing or grommet 96 of synthetic rubber having an annular groove for receiving a rolled edge of the cup. A lubricant impregnated thin nylon liner 98 is assembled inside the rubber bushing to provide a lubricated bearing and wear surface between the snubber and the bushing. As it is imperative that the mating snubber surfaces 7S, 88 be clean, the nylon insert also eliminates the presence of lubricant near the snubber surfaces.

The rubber bushing 96 has a cylindrical sidewall 100 for yieldably resisting the lateral thrust of the snubber 80 occasioned by the relative sliding movement between the snubber plate 74 and the snubber pad 88. A flange portion 102 on the bushing provides the lower stop for the snubber pad 88.

In vthe suspension system of this invention the mechanism support 56 and the snubber spring 82 are designed to each support about one-half of the weight of the mass system, i.e. the tub and its water and clothes load plus the weight of the roller drive mechanism 51. Although the snubber pad 88 may bottom out on the bushing flange 102 when the tub is standing full, these elements should be spaced apart as shown (FIGURE 2) during spin. Further, the sliding friction surfaces 78 and 88 should be freely movable relative to each other.

A relatively softer material has been chosen for the mechanism support 56 than has been used heretofore in solid tub washers. For instance, and with reference to FIGURE 7, curve A represents the hardness of the support 56 in washers exemplified by the aforementioned patents. The curves B and C represent the hardness range suitable for use with the suspension system of this invention. These curves were developed by placing the mechanism support 56 in a lixture, loading the top surface 59 thereof and measuring the distance that the top surface 59 was deected downwardly. The hardness deiined by the range between curve B and curve C in conjunction 4with the improved snubber 70 holds the critical speed of the spin tub to aronud 150 r.p.m.-a

speed more compatible for use with the slipping clutch roller drive mechanism disclosed in the concurrently filed application Ser. No. 430,264, now Patent 3,314,257 granted Apr. 18, 1967. This means the moving mass system should be supported in a manner to provide a critical speed which is suiciently low that substantially all of the water will remain in the spin tub as added ballast until after the spin tub rotates through its critical speed.

OUT OF BALANCE LOAD PROTECTION In the event that the load in the washer tub is badly out of balance at the start of spin operation, the tub will travel in an orbit as it rotates and the entire moving mass system will gyrate about a point generally at the flexible support 56. This orbital motion causes an increase in the amount of torque required to accelerate the tub to full spin sped, which results in an increased load on the clutch plate of the slipping clutch roller drive mechanism taught in Ser. No. 430,264, now Patent 3,314,257 patented Apr. 18, 1967.

As aforesaid, the merhanism support -56 is relatively softer than its counterpart in earlier design roller drive mechanisms, and is softened sufficiently to reduce the critical speed of the spin tub 34 to approximately 150 r.p.m. as compared with speeds above 200 r.p.m. in the prior structures. The softening of the mechanism support lowers the spring rate so that with a given weight of the suspended mass, the frequency of response is reduced, thereby resulting in a lower critical speed. The forces generated by the gyrations of the unbalanced spin tub are reflected at the snubber 70, where the freely movable cooperation between the snubber plate 74 and the snubber pad 8S act to snub the excursions of the lower end of the moving mass system. With the clothes washer of this invention, the resultant inertia load is always less than the force necessary to move the clothes washer cabinet 24.

During an unbalanced spin situation, the gyrations of the moving mass, including the spin tub, are limited at the support hat 56, by a restraining roller assembly 150. The roller assembly is comprised of a support bracket 152 fastened to the support housing 54 of the agitating and spinning mechanism 51. A retainer disc 154 fastened at 156 forms an annular channel or groove for cradling a nylon ring 158. If the gyrations of the moving mass become sutiicierrtly severe to effect the situation shown in FIGURE 6, the nylon ring 158 will bump into the reinforced side of the support hat 56 and rotate in its annular channel as a means to stabilize and limit the gyrations of the tub. Thus the yieldable movements of the mechanism support 56 are limited while the snubbing action is freely movable.

It should now be seen that an improved and simplified roller drive mechanism has been provided wherein the inertia forces on a moving mass system are resisted by the combination of a relatively soft mechanism support and an improved freely movable snubber arrangement for the moving mass system. Moreover, the snubber arrangement is simplied and designed in a manner to prevent contaminants from reaching the sliding friction surfaces thereof.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that order forms might be adopted.

What is claimed is as follows:

1. A washing machine including (a) casing means,

(b) a movable assembly comprising a vertical basket and slipping clutch driving means located below said basket for rotating said basket,

(c) resilient supporting means connected to said casing means below said basket and connected to said driving means at its upper portion for supporting approximately half the weight of said movable assembly,

(d) and snubber means for snubbing the movement of said movable assembly relative to said casing means,

(e) said snubber means comprising a snubber plate connected to said driving means at its lower portion, said snubber plate being free of protrusions therefrom, a snubber pad in contact with said snubber plate and freely relatively slidable thereto to permit extreme lateral movement with respect thereto due to said snubber plate being free of protrusions and positioned substantially in a horizontal plane, and means for supporting said snubber pad and the remaining weight of said movable assembly,

(f) said last named means including a cylindrical sleeve integral with said snubber pad and forming a downwardly opening pocket, a coil spring in said pocket extending between said casing means and said snubber pad for positioning said snubber pad and for vertically biasing said plate and pad together, and a resilient guide means connected to said casing means and surrounding said sleeve for resisting the lateral movement of said snubber pad and for guiding the vertical sliding movement of said sleeve,

(g) said guide means having a thin nylon facing in engagement with said sleeve for minimizing the resistance to the sliding movement of said sleeve,

(h) said guide means having a resilient stop portion between said snubber pad and said casing means for limiting the downward movement of said movable assembly,

(i) said coil spring positioning said snubber pad a spaced distance from said stop portion when said remaining weight of said movable assembly is being supported.

References Cited UNITED STATES PATENTS 2,381,894 8/1945 Ferris 68-23 X 2,519,702 8/1950' Robinson 248-21 X 2,520,442 8/1950 Schwartz 248--358 2,652,710 9/1953 De Reiner 210-365 X 2,667,269 1/1954 Reitz et al. 210-365 2,680,585 6/1954 Crede 248-21 2,859,877 11/1958 SisSon 210-365 2,896,937 7*/1959l Miller 267-1 20 sAMrH N. ZAHARNA, Primary Examiner W. S. ABRADBURY, Assistant Examiner U.S. Cl. X.R.

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